What Could Be the Side Effects of My Unrelenting Use of Ventolin?

Question

Hi. I have this problem called asthma from the time I was 2 years old. I am now 25 and for 20 years of my existence, I was just living off of 12 puffs a day of Pulmicort and Ventolin combined. I never bothered about my condition until 2 years ago, when I was leafing through a book which said that we were not supposed to take a reliever frequently and if you are taking a preventer, it is compulsory that the reliever should be used as and when required only. I am really scared now because I feel that I shouldn’t have used Ventolin that regularly even though there was no absolute necessity of it. I don’t see any problem as of now but I am worried about my future as I think it would reduce my life span. I also feel that uncertain about the consequences of the continued usage of Ventolin.
Am I right being scared? Or is there no reason for my worries? Did anybody have similar doses of medicine prescribed? Is there a way to reverse the mistake I have done and if there is, can anybody suggest what it is? Should I go ahead and visit my doctors with the previous years’ medical record?